Addison



(No Model.)

A. H. EYLES, H. S. RAPELYE & A. APPLEGATE. PROCESS OF MAKING WHITE LEAD.

Patented De0.Z1,1897f WITNESSES:

ATTORNEYS pressure.

lead will be reduced to a state of minute UNITED STATES IATENT OFFICE.

ARTHUR II. EYLES, OF PELHAMVILLE, AND HENRY S. RAPELYE AND ADDISON APPLEGATE, OF MOUNT VERNON, NEWV YORK.

PROCESS OF MAKING WHITE LEAD.

SPECIFICATION forming part of Letters Patent No. 595,849, dated December 21, 1897.

Application filed May 15, 1897. Serial No. 636,608. (No specimens.)

To all whom it may concern.-

Be it known that we, ARTHUR H. EYLES, of

'Pelhamville, and HENRY S. RAPELYE and AD- DISON APPLEGATE, of Mount Vernon,Westchester county, State of New York, have invented certain new and useful Improvements in Processes of Making Carbonate of Lead, of which the following is a specification.

Our invention relates to processes of making carbonate of lead and may be practiced as follows: Pig-lead or pure metallic lead is melted in a furnace to a state of fluidity nearly approaching the point of volatilization and is then run through a nozzle onto a stream of steam at high pressure or a stream of compressed air at a very high temperature and The result will be that the molten division. The steam or air jet is directed through a tunnel into a chamber in which the air is artificially heated and the bottom of which is covered with water preferably containing a small percentage of acidsay nitric acid or acetic acid. The particles of lead carried along by the blast rapidly oxidize and fall into the water in several stages of oxidation, as the condition of the air or the temperature of the lead may produce, so that the water will be found to contain small particles of aggregated lead, which are minute particles of lead which after division in the steam jet mass together again by impact and which, by reason of such aggregation, have not been oxidized, particles which have taken only a .small amount of oxygen and are in the form of a gray suboxid, particles which have taken the full proportion of oxygen and appear in the form of protoxid, and occasional particles which have, by reason of a high temperature, been'converted into a pink or peroxid. The acid in the water stimulates oxidation and breaks up the aggregation of lead, which is converted into the condition of hydrated oxid. This action may be accelerated by agitating the water, as by means of rakes moved backward and forward through the lead on the bottom of the chamber. In order to bring all these varying oxids comprising the mixture into the condition of protoxid, from which basic carbonate of lead can be made, the lead oxids, with five times their volume of hot water, are placed in a revolving tub, into which a volume of hot air is passed. The elements constituting the material in the tub are still in a nascent state-that is to say, the oxids have not been fixed, as they have beenunder water since their formation-and therefore under the'influence of the heat the oxids in the revolving tub readily change into protoxid, the metallic lead and the suboxids in the tub taking on more oxygen and the peroxid yielding up its superabundant oxygen. Thus the mass is made a homogeneous protoxid, in which condition alone it is capableof being converted into carbonate of lead.

For the purpose of disposing of the free acid resulting from the acidulated water in the chamber previously referred to a sufficient quantity of ammonia or some other caus tic alkali is introduced, which in the process of neutralization has been found of additional value in bringing about the protoxidation of the mass. The protoxid is then taken and placed in a tubsuch, for instance, as that forming the subject-matter of the application of A. H. Eyles, Serial No. 545,995, filed April 17, 1895-the said tub being of special construction, as hereinafter set forth. When the protoxid inadmixture with Water has been placed in the tub, the tub is revolved and the protoxid carbonized therein by the introduction of carbonic-acid gas, which is uniformly dispersed throughout the mass of protoxid and, as is well understood, will carbonize the mass, producing a hydrated carbonate of lead.

An apparatus for carrying out our invention is illustrated in the accompanying drawings and will be understood by reference thereto.

In the drawings, Figure 1 is a side elevation of the apparatus for melting and oxidizing the lead. Fig.2 is a sectional detail elevation of the tub for carbonating the lead after the said lead has been oxidized and the oxids equalized as described. Fig. 3 is a detail side elevation of a cleat employed in the tub shown in Fig. 2, and Fig.4. is a detail perspective view thereof. I

In the drawings, A represents the furnace for melting the lead, which is provided with a proper crucible B.

' slightly acidulated.

O is the air-compressor, from which a pipe D leads into the casing of the lead-furnace, where the air is heated to a very high temperature and is led from the said casing by means of a pipe E, provided with a nozzle F, discharging into a tunnel G, which leads to a chamber 11, whose contained air is heated i by extraneous means. (Not shown.) At the bottom of the chamber is a layer of water I about six or eight inches deep. Rakes I may be immersed in the said water for thepur-' pose of stirring the lead oxids which drop to the bottom of the chamber. Located above the steam-jet is a pan or sieve J, to which Y molten lead is brought from the crucible by the chamber II, where it falls into the water I, which, as before stated, is by preference The oxids are thrown into the acidulated water and kept under the said water in order to prevent them from becoming fixed before further treatment.

may not have been oxidized by the blast, the

water is slightly acidulated to assist in the corrosion of large particles of lead which may have been carried along and to promote oxidation thereof, and it has also been found that the acid is eifective to partially dissolve any peroxid which may have been formed. The slight proportion of acid used should not appear in the final product and may be 1 gotten out of the product at any stage in the 1 manipulation thereof either by being washed 1 out with water or neutralized. with a suitable alkali, as will be well understood by thosefl skilled in the art.

It will be understood that the air from the air-compressor is blown through the chamber below the crucible and is heated to a very.

high temperature thereby. The steam, in

case steam is used instead of air, is brought to the jet by means of the pipe E from any suitable source of steam-supply. chamber H the lead oxids and water may be removed to an oxidizing barrel or tub,which may be of the form shown in Fig. 2, where the oxids are treated with hot air.

the purpose of bringing the said mixed oxids to a uniform state of protoxid and is effected j as follows: The mixed oxids and water are in the revolving tub subjected to agitation, and

at the same time the heated air is brought in All these 1 contact with the agitated mass. elements acting upon the mass of oxids have The lead drops from the sieve in drops and is projected by the hot-air or steam jet issuing from 1 the nozzle F through the tunnel G and into In- 3 asmuch as the formation of hydrated oxid; will still go on from such metallic lead as From the ,1

This treat- 1 ment of the mixed oxids with hot air is for r the effect of converting the said oxids into protoxidthat is to say, the lower oxids take up oxygen and the higher oxids yield oxygen-so that the whole mass is converted into a uniform state of protoxid. .The chief novelty in our process lies in this stepthat is to say, converting the lower oxids and the higher oxids in the mass into protoxid, so as to prepare the mass for carbonization. When the oxids have been treated with heat and air and thereby brought uniformly to a protoxid, they are then removed from the oxidizing barrel or tub and placed in a similar barrel or tub, which, instead of being supplied with oxygen, is supplied with carbonic-acid gas. This tub is, as explained, similar in construction to the tub or barrel shown in Fig. 2, and the carbonic-acid gas is uniformly disbursed therethrough and reduces the protoxid to carbonate of lead.

The barrel shown in Fig. 2 may consist of an outer casing a, into which an entry-pipe b leads. This entry-pipe b is provided with apertures c, which deliver the gas to the barrel over the surface of a convex bell cZ,which bell serves to spread and dissipate the gas and prevent the same from blowing in a small stream through the barrel, which spreading of the gas will bring the same into contact with the sides of the barrel. A similar bell e is located at the opposite end of the barrel and is affixed to an exit-pipe f, which is provided with apertures g for allowing the gas to escape from the barrel into the exit-tube f, the convex bell e serving the same purpose as the convex bell (Z. Mounted upon the walls of the barrel are cleats 7t. (Shown in detail in Figs. 3 and 4.) These cleats are of a peculiar construction, in order to overcome a difficulty existent in oxidizing tubs or barrels of this character. In the ordinary oxidizing revolving tub the masses of oxid, being glutinous, were carried around by the cleats without dropping through the current of gas passing through the barrel, or if they did drop did so in a mass, and therefore failed to properly oxidize. To overcome this difficulty, we have provided the cleats 71. with pegs z', projecting from their upper surfaces and their edges,which pegs prevent the glutinous mass from falling from the oleat in a mass and divide the same, so that as it falls through the body of the barrel it will be properly divided, so as to be suliiciently oxidized.

\Ve have not as yet been able to determine with absolute accuracy the reactions at any given moment or the chemical formula of the mass during manufacture. \Vhen the lead has been blown into the acidulated water, the aggregated mass at the bottom of the water has a gray orv grayish-black color in which a greenish tinge appears, and likewise a pink color frequently appears. Now in accounting for these various colors it is not IIO quite possible to state the exact chemical condition of the mass. fectly clear that the gray coloris due to the For instance, it is perpreponderance of the gray suboxid of lead Pb O and metallic lead, which is bluish gray. The greenish tinge may representaformation approximating the formula Pb O or it may arise from the mechanical admixture of Pb O, which is the gray suboxid, and PbO, the protoxid, which, as is well known, is yellow. It is undoubtedly true that protoxid is formed, and frequently when atmospheric and other conditions are favorable the peroxid PbO which is of a pink color, is formed, but usually under ordinary conditions, in quite a limited amount. In determining the degree of oxidation it is our practice to be governed wholly by the color of the mass, so that when the mass takes on a yellow color we know that the oxidation is proceeding far enough to be called a uniform protoxid, although it is quite possible that traces of other oxids may be found in the mass.

Having described our invention, what we claim, and desire to secure by Letters Patent, 1s

1. The herein-described process of manufacturing carbonate of lead, the same consisting in oxidizing the lead by feeding the same in a molten state closely approaching volatilization into a stream of fluid at high temperature and pressure and carrying the same along in the stream, whereby the lead is oxidized to difierent degrees of oxidation, dropping the said mixture of oxids into a fluid whereby the said oxids will not become fixed, and subsequently converting the said mixture of oxids into a uniform state of protoxid and thereupon carbonating the protoxid so produced.

2. The herein-described process of manufacturing protoxid of lead, which consists in heating the lead to a molten condition closely approaching volatilization, feeding the said lead while in such highly-heated condition into a stream of fluid at high temperature and pressure-and carrying the same along in the stream thereby oxidizing the lead to different degrees of oxidation, dropping the saidmixture of oxids into a fluid which will prevent said oxids from becoming fixed and thereupon heating the said mixture of oxids and simultaneously agitating the same to convert the said mixture of oxids into a uniform protoxid of lead.

' ARTHUR H. EYLES.

HENRY SJRAPELYE. ADDISON APPLEGATE. Witnesses:

HORACE P. HOLLISTER, CHRISTIAN D. MORGAN. 

